Pumps are used in many applications for moving various types of fluids. For example, pumps are used in pipeline systems that supply water to boilers. Pumps are also used in pipeline systems that circulate cooling water for coolers and condensers and transferring fuel oil. Many chemical processes employ pumps in pipelines that circulate industrial chemicals in reactors, distribution columns, kettles and the like.
One commonly known pump for moving fluids in pipeline systems is a canned rotor (motor) inline pipe pump. A typical canned rotor inline pipe pump includes a motor positioned on one side of a pump. The motor has an enclosed or canned rotor with a drive shaft that is coupled to the pump's impeller for rotation thereof, and an enclosed or canned stator which peripherally surrounds the canned rotor. Fluid pumping is achieved through electromagnetic interaction between the canned rotor and the canned stator which produces high speed rotation of the rotor. The rotation of the rotor causes the impeller to rotate via the drive shaft which couples the impeller to the rotor.
Canned rotor pumps utilize a portion of the pump-treating fluid which is typically withdrawn from the suction port of the pump section and circulated through the motor to lubricate the motor and drive shaft bearings as well as remove heat which is generated due to the inefficiency of the motor. This portion of the fluid is then reintroduced into the suction port of the pump section.
There are some disadvantages associated with conventional canned rotor pumps. The drive shaft's bearings and other related mechanical components add complexity and increase the cost of such pumps. Further, the drive shaft and its related components can require a considerable amount of maintenance. Additionally, the drive shaft increases the length of the pump, thus limiting the available location of the pump in pipeline systems.
Pumps traditionally mounted on a baseplate can be subjected to many external forces and moments due to excessive pipe loads. These forces and moments can lead to premature pump failure. If the pump can reside within the piping system, all pipe loads will be eliminated.
Therefore, a need exits for a shaftless canned rotor inline pipeline pump.